Fig. 1.

Summary of the framework underlying this systematic review and methodological design of the included studies. Based on the experimental and epidemiological evidence, the figure illustrates the potential prospective relationship between changes in sleep and chronic pain experience. Changes in sleep from baseline to follow-up represents the variable predicting subsequent chronic pain experience. Change in sleep* refers to change in i) sleep duration, ii) sleep quality, and/ or iii) insomnia symptoms. Pain-related health outcomes^# represents the factors that make up overall pain experience, namely, the risk of developing a pain condition, changes in physiological inflammatory and immune processes and changes in self-reported pain-related health and functioning status.